As per the customs act it's totally illegal. Any model body (kabli) which is being imported without the tax being paid, is illegal to be mounted on any registered frame. People have been paying custom taxes on registered jimnys', parados', crowns and without the tax it is illegal. You put a jimny on the frame of potohar, its illegal without the body tax. or put a wrangler on the frame of CJ 7, it's illegal. And about the frame. It can be altered legally. There are rules and regulations as per custom's act and as pet ETO's office. All the extended jeeps at northern areas are extended versions of the frame of CJ5/ CJ6 or CJ7. Suzuki sj 410's frame can also be extended to make it a long wheel base.